Compressed-air brake line

Abstract

A compressed-air brake line which comprises: I) an external layer made of a moulding composition which comprises at least 50% by weight of PA11 and/or PA12, and II) an internal layer made of a moulding composition which comprises at least 50% by weight of polyamide whose monomer units comprise on average at least 8 C atoms is provided. Layer II) does not contain PA11 and/or PA12. The compressed-air brake line has high bursting strength even at elevated temperature, good low-temperature impact resistance, good ageing resistance, and can be produced at low cost.

1 . A compressed-air brake line, comprising:
 I. an external layer having a moulding composition which comprises at least 50% by weight of PA11 and/or PA12, and   II. an internal layer having a moulding composition which comprises at least 50% by weight of a polyamide whose monomer units comprise on average at least 8 C atoms, with the proviso that PA11 and PA12 are not included.   
     
     
         2 . The compressed-air brake line according to  claim 1 ,
 further comprising:   III. an innermost layer having a moulding composition which comprises at least 50% by weight of polyamide whose monomer units comprise on average at least 8 C atoms.   
     
     
         3 . The compressed-air brake line according to  claim 1 ,
 wherein the external layer I further comprises a copper-containing stabilizer.   
     
     
         4 . The compressed-air brake line according to  claim 3 ,
 wherein the internal layer II further comprises a copper-containing stabilizer.   
     
     
         5 . The compressed-air brake line according to  claim 2 ,
 wherein the innermost layer III comprises a copper-containing stabilizer.   
     
     
         6 . The compressed-air brake line according to  claim 3 , wherein
 a copper content of the external layer I is from 0.001 to 0.05% by weight.   
     
     
         7 . The compressed-air brake line according to  claim 4 , wherein
 a copper content of the internal layer II is from 0.001 to 0.05% by weight.   
     
     
         8 . The compressed-air brake line according to  claim 5 , wherein
 a copper content of the innermost layer I is from 0.001 to 0.05% by weight.   
     
     
         9 . The compressed-air brake line according to  claim 1 , further comprising:
 an adhesion-promoter layer bonding the layers I and II to one another.   
     
     
         10 . The compressed-air brake line according to  claim 2 , further comprising:
 an adhesion-promoter layer bonding the layers II and III to one another.